Generalized sensory sensitivity is associated with comorbid pain symptoms: a replication study in women with dysmenorrhea

Central Sensitivity Symptoms and Autistic Traits in Autistic and Non-Autistic Adults

Central sensitivity syndromes (CSSs) are a group of health conditions thought to include an underlying sensitisation of the central nervous system. Evidence suggests autistic adults experience poorer physical health than the general population and are more likely to have a CSS. This study examined CSS diagnoses and symptoms in autistic and non-autistic adults, to determine whether CSS symptoms were related to autistic traits, mental health, sensory sensitivity, age or gender. Participants included 534 adults with clinical diagnoses of autism, CSS, both diagnoses or neither (i.e., comparison group), who were recruited through social media, support groups and institutional affiliations. Participants completed online self-report validated questionnaires, including the Autism Spectrum Quotient (AQ), Central Sensitization Inventory (CSI), Sensory Perception Quotient (SPQ), and the PHQ-9 and GAD-7. Autistic people without a diagnosed CSS reported significantly more CSS symptoms than the comparison group, with a mean score above the clinical cut-off. Non-autistic participants with a CSS had significantly more autistic traits than the comparison group. Autistic people with a CSS reported the most sensory sensitivity, with autism only and CSS only groups reporting similar levels of sensory sensitivity and all diagnostic groups reporting more sensory sensitivity than the comparison group. Sensory sensitivity, anxiety, autistic traits, age and gender were all significant predictors of CSS symptoms. The overlap in symptoms between autistic individuals and those with CSS suggests diagnostic overshadowing and possible under-diagnosis or misdiagnosis. Furthermore, these symptoms may exacerbate or mask one another. Notwithstanding potential limitations of representativeness and selection bias, increased awareness of the association between autistic traits and CSS symptoms is important for clinicians to improve diagnostic accuracy and treatment.

Multisensory sensitivity in relation to pain: a scoping review of terminology and assessment

Chronic pain is a debilitating health problem affecting 20 million Americans annually. Most patients with chronic pain report negative impacts on daily function and quality of life, which can result in devastating emotional and financial stress. Although the causes of chronic pain remain elusive, there is increasing interest in sensitivity to everyday sensory stimuli as it relates to chronic pain, potentially serving as an indirect marker of altered central nervous system sensory processing. However, sensitivity to multiple sensory inputs, eg, bright lights, certain fabrics, loud noises, etc, is described using multiple terminologies. The lack of a common vocabulary makes it difficult to find and summarize related discoveries, potentially inhibiting scientific progress. Thus, the purpose of this scoping review was to identify and characterize the terminology used in publications assessing some form of multisensory sensitivity as it relates to pain (eg, a pain cohort or pain sensitivity). Our review of 6 databases (PubMed, Scopus, Embase, CINAHL, PsycINFO+, and Cochrane) comprehensively cataloged peer-reviewed studies published through March 2023 in this domain. Of 12,841 possible studies identified, 92 met all inclusion criteria, with over 80% being published in the last decade. A wide range of terminology has been used for this construct, likely in part a result of the many different professional disciplines represented. These results provide valuable insights for future development of a standardized vocabulary and serve as a resource to aid future investigators of multisensory sensitivity and pain in their study design.

Deciphering nociplastic pain: clinical features, risk factors and potential mechanisms

Nociplastic pain is a mechanistic term used to describe pain that arises or is sustained by altered nociception, despite the absence of tissue damage. Although nociplastic pain has distinct pathophysiology from nociceptive and neuropathic pain, these pain mechanisms often coincide within individuals, which contributes to the intractability of chronic pain. Key symptoms of nociplastic pain include pain in multiple body regions, fatigue, sleep disturbances, cognitive dysfunction, depression and anxiety. Individuals with nociplastic pain are often diffusely tender - indicative of hyperalgesia and/or allodynia - and are often more sensitive than others to non-painful sensory stimuli such as lights, odours and noises. This Review summarizes the risk factors, clinical presentation and treatment of nociplastic pain, and describes how alterations in brain function and structure, immune processing and peripheral factors might contribute to the nociplastic pain phenotype. This article concludes with a discussion of two proposed subtypes of nociplastic pain that reflect distinct neurobiological features and treatment responsivity.

A comprehensive investigation of biopsychosocial determinants influencing primary dysmenorrhea among university students

Dysmenorrhea, characterized by pain and related symptoms, significantly impacts women's quality of life in work and education, prompting a comprehensive evaluation of associated factors. The objective of this study was to utilize structural equation modeling (SEM) to analyze and assess the biopsychosocial factors influencing dysmenorrhea among university students. Three hundred and thirty-nine university students were included in this cross-sectional descriptive study. Data were collected using the Participant Information Form, the Beck Anxiety Scale (BAS), the Beck Depression Scale (BDS), the Multidimensional Scale of Perceived Social Support (MSPSS), the Adverse Childhood Experiences Scale (ACES), the Pain Catastrophizing Scale (PCS) and the Visual Analogue Scale (VAS). It was determined that the variables of pain onset (t = 3.24, p < .05) and age at menarche (t = -2.16, p < .05) showed a significant relationship with the model. The variables of the PCS (t = 16.87, p < .001), BDS (t = 3.06, p < .05), and BAS (t = 5.13, p < .001) showed a significant relationship with the model. Social factors in the model were examined, and a family history of dysmenorrhea and the ACES variables did not contribute significantly to the model (p > .05). The study indicates primary dysmenorrhea influenced by biological and psychological factors. Nurses should conduct holistic assessments and provide comprehensive care for affected women.

Fibromyalgia is linked to increased subjective sensory sensitivity across multiple senses

Changes in subjective sensory sensitivity - reporting sensory stimuli as being atypically intense or weak - are a transdiagnostic symptom of several disorders. The present study documents for the first time the sensory sensitivity profile of fibromyalgia, taking a questionnaire measure that asks about different sensory modalities and both hyper- and hyposensitivity (the Glasgow Sensory Questionnaire, GSQ). The fibromyalgia group had higher overall scores on this measure. This was linked more strongly to sensory hypersensitivity and was pervasive across all senses that were surveyed. Although differences in hyposensitivity were found, these were sporadic (perhaps linked to the symptoms of fibromyalgia itself) and did not resemble the pattern documented for autism (e.g., self-stimulating and repetitive behaviours were not a feature of fibromyalgia). We suggest that individual differences in subjective sensory hypersensitivity may be a multisensory dispositional trait linked to fibromyalgia which ultimately becomes most pronounced for pain.

Repurposing of Bryophyllum pinnatum for dysmenorrhea treatment: a systematic scoping review and case series

Dysmenorrhea affects women throughout their reproductive years but there has been a lack of effective and well-tolerated treatment options. Pain symptoms mainly result from inflammatory processes and increased contractile activity in the myometrium. The reported use of Bryophyllum pinnatum preparations against inflammation and pain in ethnomedicine as well as current pharmacological data on their inhibition of myometrial contractility led us to hypothesize that this medicinal plant might be a new treatment option for dysmenorrhea. In the first part of the present work, clinical, in vivo, and in vitro studies on the anti-nociceptive and anti-inflammatory, as well as on myometrium relaxing properties of B. pinnatum are reviewed. In the second part, cases of five women with dysmenorrhea who were tentatively treated with a B. pinnatum product are described. The review revealed thirty-three experimental in vivo and in vitro studies, but no clinical study, reporting anti-nociceptive and anti-inflammatory effects of B. pinnatum extracts and compounds in a wide range of conditions. Moreover, sixteen publications on smooth muscle contractility revealed relaxing effects. The latter consisted of clinical evidence, as well as of in vivo and in vitro data. The evidence reviewed therefore provided a rational basis for the use of B. pinnatum in the treatment of dysmenorrhea. We subsequently set out to tentatively treat patients with a well-tolerated B. pinnatum product that is registered (without indication) and commonly used in obstetrics and gynecology in Switzerland. All five treated patients reported a reduction in pain symptoms and 4 out of 5 indicated a reduced intake of painkillers during menstruation. Taken together, the reviewed information on the pharmacological properties and clinical evidence of B. pinnatum extracts and compounds as well as the outcomes of all five patients in the case series support our hypothesis in favor of B. pinnatum as a new, well-tolerated therapeutic approach for dysmenorrhea. Prospective clinical studies are urgently needed.

Predicting chronic postsurgical pain: current evidence and a novel program to develop predictive biomarker signatures

ABSTRACT

Chronic pain affects more than 50 million Americans. Treatments remain inadequate, in large part, because the pathophysiological mechanisms underlying the development of chronic pain remain poorly understood. Pain biomarkers could potentially identify and measure biological pathways and phenotypical expressions that are altered by pain, provide insight into biological treatment targets, and help identify at-risk patients who might benefit from early intervention. Biomarkers are used to diagnose, track, and treat other diseases, but no validated clinical biomarkers exist yet for chronic pain. To address this problem, the National Institutes of Health Common Fund launched the Acute to Chronic Pain Signatures (A2CPS) program to evaluate candidate biomarkers, develop them into biosignatures, and discover novel biomarkers for chronification of pain after surgery. This article discusses candidate biomarkers identified by A2CPS for evaluation, including genomic, proteomic, metabolomic, lipidomic, neuroimaging, psychophysical, psychological, and behavioral measures. Acute to Chronic Pain Signatures will provide the most comprehensive investigation of biomarkers for the transition to chronic postsurgical pain undertaken to date. Data and analytic resources generatedby A2CPS will be shared with the scientific community in hopes that other investigators will extract valuable insights beyond A2CPS's initial findings. This article will review the identified biomarkers and rationale for including them, the current state of the science on biomarkers of the transition from acute to chronic pain, gaps in the literature, and how A2CPS will address these gaps.

Multimodal hypersensitivity derived from quantitative sensory testing predicts pelvic pain outcome: an observational cohort study

ABSTRACT

Multimodal hypersensitivity (MMH)-greater sensitivity across multiple sensory modalities (eg, light, sound, temperature, pressure)-is associated with the development of chronic pain. However, previous MMH studies are restricted given their reliance on self-reported questionnaires, narrow use of multimodal sensory testing, or limited follow-up. We conducted multimodal sensory testing on an observational cohort of 200 reproductive-aged women, including those at elevated risk for chronic pelvic pain conditions and pain-free controls. Multimodal sensory testing included visual, auditory, and bodily pressure, pelvic pressure, thermal, and bladder pain testing. Self-reported pelvic pain was examined over 4 years. A principal component analysis of sensory testing measures resulted in 3 orthogonal factors that explained 43% of the variance: MMH, pressure pain stimulus response, and bladder hypersensitivity. The MMH and bladder hypersensitivity factors correlated with baseline self-reported menstrual pain, genitourinary symptoms, depression, anxiety, and health. Over time, MMH increasingly predicted pelvic pain and was the only component to predict outcome 4 years later, even when adjusted for baseline pelvic pain. Multimodal hypersensitivity was a better predictor of pelvic pain outcome than a questionnaire-based assessment of generalized sensory sensitivity. These results suggest that MMHs overarching neural mechanisms convey more substantial long-term risk for pelvic pain than variation in individual sensory modalities. Further research on the modifiability of MMH could inform future treatment developments in chronic pain.

Looking at fibromyalgia differently - An observational study of the meaning and consequences of fibromyalgia as a dimensional disorder

OBJECTIVE

Despite data showing that fibromyalgia can be represented as a dimensional disorder, almost all assessments treat fibromyalgia as a dichotomous categorial disorder; and research shows that agreement between community diagnosis of fibromyalgia and fibromyalgia criteria is poor. We investigated the validity of FM as a discrete disorder by exploring the relationships of categorical fibromyalgia, the polysymptomatic distress (PSD) scale, and clinical variables.

METHODS

In a databank of 33,972 rheumatic disease patients, we studied the categorical diagnosis of fibromyalgia, the PSD scale separately and divided into severity groups, measures of widespread pain, as well as somatic syndrome questionnaires like the Patient Health Questionnaire-15 (PHQ-15), and clinical pain, global, HAQ disability and quality of life scales (EQ-5D).

RESULTS

Clinical and demographic variables became more abnormal with increasing PSD score groups, indicating substantial increase in symptoms and pain. The changes across PSD categories were linear and large. When we compared FM- (PSD 8-11) with FM+ (PSD 12-18) patients we found considerable overlap in scores for pain, HAQ disability, patient global, PHQ-15, psychological status, and other variables. Somatic symptom scores were highly correlated with PSD (r=0.718). There was no evidence of a differential pain effect that was present in FM+ but not FM- subjects.

CONCLUSION

Fibromyalgia is more accurately considered a dimensional than a dichotomous disorder. There is vast variability among fibromyalgia positive and negative cases that is governed by the strong and linear relationships between the dimensional PSD scale and clinical variables. The PSD scale provides measurements of the fibromyalgia dimension that support and enlighten categorical fibromyalgia and are an effective tool to measure clinical status and changes. Whatever the mechanism of the pain and symptom increase in fibromyalgia, it appears to operate over the entire fibromyalgia symptom dimension, not just in those with categorical fibromyalgia.